ok so here is goes....
if u have a tank full of all diff types of fish.. just wondering now... if you have several fry from all types of live breeders and only a few fry make it every batch .. wont that be the strongest fry? and if so would you not be keeping only the best of each litter? so then if the best from each hatching make it and so on in a few years would u not have superior fish

let me know what ya think? if this is so then i would not want to sep my fry and hope that they are strong enough to make it .. of couse i have lots of places for then to hide like in the wild! so its like they do have a great fighting chance? lemme know?
JD